This invention relates in general to subsea well installations and particularly to the establishment of a connection between a marine conductor run from an overhead platform to a subsea wellhead.
Various types of connectors have been developed heretofore for connecting a marine conductor or riser to a subsea wellhead, as the connector disclosed in prior U.S. Pat. No. 3,333,870. It has been known heretofore to run marine conductors and their associated marine connector by guidelines from floating vessels to the wellhead, or in shallower subsea well operations in run the conductor or riser from the overhead fixed platform down to the wellhead. A similar operation is conducted in tieback systems used after well drilling and completion stages. It has also been found that the marine conductor or conduit is not always conveniently aligned over the wellhead due to the buildup of tolerances in guiding mechanisms or the influence of ocean currents and/or winds on the vessel or platform. It has therefore been deemed to be desirable to be able to shift or move the lower end of the marine conductor or conduit in a determinable manner while in the subsea environment to align its associated marine connector to the wellhead to facilitate landing of the connector on the wellhead by further lowering of the marine conductor or conduit from the overhead platform or vessel.
In addition, in the directional drilling operations where a curved conductor pipe is to be used, it has been suggested that there is a need for a bending tool which could be inserted within the curved pipe to straighten it during the step of insertion of the conductor pipe through straight guides of the drilling platform. After the temporarily straightened conductor pipe is inserted through the straight guides of the platform the conductor pipe is allowed to reassume its curved configuration for conducting a directional drilling. It is an object of the present invention to disclose and provide a bending tool which may be used therefore in such a way that the tool can be inserted in the curved conductor pipe, hydraulic fluid applied to the tool to straighten the pipe temporarily during mounting to the platform guides ahd then be removed after relief of the hydraulic fluid pressure exerted on the tool, thus allowing the conductor to return to its original curved configuration. In this use for the bending tool of the present invention, the tool is employed to straighten a curved pipe for assembly of the pipe through guides. It is a primary object of the present invention to disclose and provide a method of curving an otherwise straight conductor in a subsea well location environment through the use of an internally operated bending tool to align an end of the conductor to the wellhead.
It is a further object of the present invention to disclose and provide a method of aligning the lower end of a marine conductor or conduit, even at great depths in the sea, over and adjacent a wellhead to which it is to be connected by operations from a remotely located overhead platform which may be fixed above the sea. It is contemplated within the present invention to provide a new marine conductor bending tool, and a new method of bending the marine conductor or marine conduit while it is suspended from an overhead platform or vessel and extending deeply into the sea by use of the bending tool in a new manner to achieve a new result in aligning and connecting marine conductor couplings to subsea wellheads located on the floor of the sea.